Theodore Roosevelt Jr., often referred to as Teddy or by his initials, T. R., was an American politician, statesman, conservationist, naturalist, and writer who served as the 26th president of the United States from 1901 to 1909. He previously held various positions in New York politics, rising up the ranks to serve as the state's 33rd governor for two years. He later served as the 25th vice president under President William McKinley for six months in 1901, assuming the presidency after McKinley's assassination. As president, Roosevelt emerged as a leader of the Republican Party and became a driving force for anti-trust and Progressive policies.

The president of the United States (POTUS) is the head of state and head of government of the United States of America. The president directs the executive branch of the federal government and is the commander-in-chief of the United States Armed Forces.